Anatomical studies demonstrate selective compartmental innervation of most human extraocular muscles (EOMs), suggesting the potential for differential compartmental control. This was supported by magnetic resonance imaging (MRI) demonstrating differential lateral rectus (LR) compartmental contraction during ocular counterrolling, differential medial rectus (MR) compartmental contraction during ...

purpose: to report a patient with exotropia due to medial rectus muscle entrapment as a complication of endoscopic dacryocystorhinostomy (edcr). case report: a 34-year-old female was referred with left exotropia 18 days after edcr for treatment of primary nasolacrimal duct obstruction. she had a large angle left exotropia in primary position as well as complete limitation of adduction and parti...

Address for Correspondence: Edward Ridyard, 9 The Meadows, Rainhill, Prescot, L35 0PQ, UK. E-Mail: [email protected] Foundation Year 2 doctor, Oxford University Hospitals, Prescot, UK. Background: The extraocular muscles (EOMs) bring about eye movement and studies exist which measure EOM length, cross-sectional diameter and volume. Knowledge of the normal values is crucial for deter...

BACKGROUND The association of oblique palpebral fissures and A- or V-pattern has not been clarified. We report two cases of A-pattern esotropia with marked mongoloid slanting palpebral fissures associated with vertical displacement of the horizontal rectus muscle. CASES Case 1 was a boy with Prader-Willi syndrome. He showed A-pattern esotropia with upward slanting palpebral fissures. Severe s...

To the Editors: Acquired progressive esotropia in patients with high myopia1 is caused by conversion of lateral rectus muscle function from abduction to infraduction, leading to impaired abduction and supraduction.2 Imaging techniques have revealed abnormal extraocular muscle position in these patients; the lateral rectus muscle is displaced inferiorly and the superior rectus muscle is shifted ...

The rectus extraocular muscle (EOM) pulleys constrain EOM paths. During visual fixation with head immobile, actively controlled pulleys are known to maintain positions causing EOM pulling directions to change by one-half the change in eye position. This pulley behavior is consistent with Listing's law (LL) of ocular torsion as observed during fixation, saccades, and pursuit. However, pulley beh...

IMPORTANCE Recognition of sagging eye syndrome (SES) as the cause of chronic or acute acquired diplopia may avert neurologic evaluation and imaging in most cases. OBJECTIVES To determine whether SES results from inferior shift of lateral rectus (LR) extraocular muscle (EOM) pulleys and to investigate anatomic correlates of strabismus in SES. DESIGN AND SETTING We used magnetic resonance ima...